After-hours buzz: Gap, IMAX, Cigna & more

Check out the companies making headlines after the bell Monday:

Gap - The retailer said itwill close 26 percent of its North American namesake stores over the next several years in an effort to streamline its store fleet. Shares rose more than 1 percent after the announcement.

Under Armour - The athletic apparel maker created a new, non-voting class of common stock. Under Armour plans to issue the new class C stock to all current stockholders, which will have the same effect as a two-for-one stock split, the company said. Shares rose modestly after hours.

IMAX - The entertainment provider said IMAX box office sales for Universal Pictures' "Jurassic World" were a record-setting $23.2 million, beating the previous best of $16.7 million. That helped send shares nearly 1 percent higher during the regular session. They gave up those gains after hours. (Disclosure: Universal Pictures is a subsidiary of NBCUniversal, CNBC's parent company.)

Cigna - The health services firm's stock rose modestly in extended trading after surging more than 11 percent during the regular session on reports that it rebuffed a takeover reproach by Anthem.